I have a light switch based in the UK and all of them have three wires to that go into the switch. I think one is a load and one is alive. Is that correct and then I also have a green/yellow which is...

@chr0m4t1c so I have three wires in my switch. I think one is black and one is blue and the last is the green/yellow. i assume the black is the load and the blue is the live? bt the ground. Where...